Man seen for progressive unilateral proptosis, redness and high IOP

The left eye showed 360° of injection with corkscrew-like, dilated, tortuous conjunctival vessels and periorbital edema.

Mark E. Patron

Andre J. Witkin

A 70-year-old man initially presented to his ophthalmologist for several years of poor vision in both eyes, for which he was diagnosed with bilateral brunescent cataracts. The patient was scheduled for cataract surgery in his right eye but began noticing left eye swelling and redness 6 weeks before surgery and decreased vision in the left eye. The patient also began to note binocular diplopia around this time.

A few days before cataract surgery, the patient was noted by his ophthalmologist to have proptosis, redness and tenderness of the left eye, as well as a left eye IOP of 40 mm Hg. The patient was placed on Xalatan (latanoprost, Pfizer) and Combigan (brimonidine tartrate, timolol maleate, Allergan) for his high pressure and was subsequently transferred to the New England Eye Center for evaluation. His medical history was significant for congestive heart failure, coronary artery disease, chronic obstructive pulmonary disease and diabetes.

Examination

On examination, the patient’s best corrected visual acuity was 20/400 in the right eye and counting fingers at 3 feet in the left. IOPs were 16 mm Hg and 24 mm Hg, respectively. Pupillary exam was normal with no afferent pupillary defect. There was 4 mm of relative proptosis on his left side. Extraocular movements revealed limited movement of the left eye in all cardinal gazes. No ocular bruits were heard, and facial sensation was grossly intact bilaterally.

On slit lamp exam, the left eye showed 360° of injection with corkscrew-like, dilated, tortuous conjunctival vessels and periorbital edema (Figures 1a and b). Both lenses showed dense, brunescent nuclear sclerosis. The fundus was not easily viewed through the dense cataracts, but there were scattered blot hemorrhages around the posterior pole in his left eye. No obvious optic disc edema was noted.

Figure 1a. Diffuse conjunctival injection and eyelid edema.

Figure 1b. Corkscrew dilated conjunctival vessels. Images: Chen J, Hedges TR

What is your diagnosis?

Ophthalmoplegia, proptosis

The differential diagnosis of a patient with unilateral proptosis, injection and ophthalmoplegia includes carotid-cavernous sinus shunts, orbital cellulitis with or without cavernous sinus thrombosis, orbital tumors, thyroid ophthalmopathy and idiopathic orbital inflammation, including Tolosa-Hunt syndrome.

Carotid-cavernous sinus fistulas or dural shunts may present with signs of ocular bruits on exam. Cavernous sinus thrombosis and orbital cellulitis are typically complications of an infection of the face or paranasal sinuses, and patients with cavernous sinus thrombosis may present with meningeal signs and mental status changes. Thyroid ophthalmopathy can present with ophthalmoplegia and proptosis, and any spheno-orbital mass lesion such as a meningioma is possible, but the time course for this patient’s condition is too short for either of these diagnoses. Tolosa-Hunt syndrome is a condition of nonspecific inflammation within the cavernous sinus or superior orbital fissure and is usually a diagnosis of exclusion.

A CT of the orbits revealed a large superior ophthalmic vein in the left orbit (Figure 2). Angiogram showed a left-sided dural shunt (Figure 3).

Figure 2. CT orbits showing dilated left superior ophthalmic vein.

Figure 3. Left external carotid showed abnormal arteriovenous shunting from branches of the left internal maxillary artery to the wall of the cavernous sinus and drainage anteriorly into the left superior ophthalmic vein (black arrow).

Discussion

Dural shunts are abnormal communications between the internal or external carotid arteries and the cavernous sinus. Shunts can be classified according to their etiology (traumatic vs. spontaneous), velocity of blood flow (high vs. low) and anatomy (internal vs. external carotid).

Direct carotid-cavernous sinus fistulae are traumatic or spontaneous rents in the walls of the intracavernous internal carotid artery and involve high rates of arterial blood flow. They are most commonly caused by a single traumatic tear in the arterial wall. Dural carotid-cavernous sinus shunts are communications between the cavernous sinus and one or more meningeal branches of the internal carotid artery, external carotid artery or both. They involve lower rates of arterial blood flow and almost always produce symptoms and signs spontaneously, without any antecedent trauma or manipulation.

The typical presentation of dural shunts includes a red eye, diplopia, an ocular bruit, decreased vision, proptosis and facial pain in the distribution of the first division of the trigeminal nerve. Other findings may involve eyelid edema, conjunctival arterialization and chemosis, central retinal vein occlusion and elevated IOP.

Dural shunts usually occur in middle-aged women, but may produce symptoms at any age and in both sexes. Predisposing factors include pregnancy, hypertension, atherosclerotic vascular disease, connective tissue diseases such as Ehlers-Danlos syndrome and minor trauma. Visual loss occurs in 20% to 30% of patients with dural carotid-cavernous sinus fistulae and may be due to secondary ischemic optic neuropathy, chorioretinal dysfunction or uncontrolled glaucoma.

Most patients with a dural shunt have no difference in mortality from the normal population, and about 20% to 50% of dural shunts close spontaneously after angiography. Patients who have mild ocular manifestations can be clinically followed to see if the fistula will close spontaneously.

Treatment

Endovascular embolization is the optimum treatment for dural shunts, and the transvenous approach has a higher success rate with a relatively lower likelihood of serious complications compared with transarterial embolization. Direct surgery, radiation therapy and stereotactic radiosurgery are less often used.

Symptoms usually begin to improve within hours to days after closure of the fistula. Eyelid engorgement, conjunctival chemosis, dilated conjunctival vessels and elevated IOP generally return to normal within weeks to months.

References:

• Debrun GM, Viñuela F, Fox AJ, Davis KR, Ahn HS. Indications for treatment and classification of 132 carotid-cavernous fistulas. Neurosurgery. 1988;22(2):285-289.
• de Keizer R. Carotid-cavernous and orbital arteriovenous fistulas: ocular features, diagnostic and hemodynamic considerations in relation to visual impairment and morbidity. Orbit. 2003;22(2):121-142.
• Grove AS Jr. The dural shunt syndrome. Pathophysiology and clinical course. Ophthalmology. 1984;91(1):31-44.
• Higginbotham EJ. Glaucoma associated with increased episcleral venous pressure. In: Albert DM, Jakobiec FA, eds. Principles and Practice of Ophthalmology. 2nd ed. 2000:2781-92.
• Ishijima K, Kashiwagi K, Nakano K, Shibuya T, Tsumura T, Tsukahara S. Ocular manifestations and prognosis of secondary glaucoma in patients with carotid-cavernous fistula. Jpn J Ophthalmol. 2003;47(6):603-608.
• Keltner JL, Satterfield D, Dublin AB, Lee BC. Dural and carotid cavernous sinus fistulas. Diagnosis, management, and complications. Ophthalmology. 1987;94(12):1585-1600.
• Kirsch M, Henkes H, Liebig T, et al. Endovascular management of dural carotid-cavernous sinus fistulas in 141 patients. Neuroradiology. 2006;48(7):486-490.
• Miller NR. Carotid-cavernous sinus fistulas. In: Miller NR, ed. Walsh and Hoyt’s Clinical Neuro-Ophthalmology. 4th ed. Baltimore: Williams; 1991:2165-209.
• Miller N. Carotid-cavernous sinus fistula. In: Miller N and Newman N, eds. Clinical Neuro-Ophthalmology. 6th ed. London: Lippincott; 2005:2262-2290.
• Rai AT, Sivak-Callcott JA, Larzo C, Marano GD. Direct carotid cavernous fistula in infancy: presentation and treatment. AJNR Am J Neuroradiol. 2004;25(6):1083-1085.
• Troost BT, Glaser JS, Morris PP. Aneurysms, arteriovenous communications, and related vascular malformations. In: Glaser, ed. Neuro-ophthalmology. 3rd ed. Philadelphia: Lippincott Williams & Wilkins; 1999:589-628.

• John Chen, MD, and Thomas R. Hedges III, MD, can be reached at New England Eye Center, Tufts University School of Medicine, 750 Washington St., Box 450, Boston, MA 02111; Web site: www.neec.com.
• Edited by Mark E. Patron, MD, and Andre J. Witkin, MD. They can be reached at New England Eye Center, Tufts University School of Medicine, 750 Washington St., Box 450, Boston, MA 02111; Web site: www.neec.com.